Controlled multiple switching unit



March 30, 1965 H.- c. HANSON ETAL 3,176,091

CONTRQLLED MULTIPLE SWITCHING UNIT Filed Nov. '7, 1962 2 Sheets-Sheet l FIGI i. Illill .il

7 11 IEILHINLIEI 14 N I! n I FIGG INVENTORS HELMER C. HANSON ANDREW J. KMETZ OWM FIGZ

ATTORNEY March 30, 1965 H. c. HANSON ETAL 3,176,091

CONTROLLED MULTIPLE SWITCHING UNIT Filed Nov. 7, 1962 2 Sheets-Sheet 2 FIGS 22 26 l 25 FIG] h Ii lull l All "llllllllllllll llllllllllllll lf ama l 40 INVENTORS HELMER c. HANSON BY ANDREW .1. KMETZ A TTORNE Y United States Patent 3,176,091 CONTROLLED MULTIPLE SWITCHING UNIT Helmer C. Hanson, 34-22 Dover Road, and Andrew J. Kmetz, 3333 Dunn, both of Cheyenne, Wyo. Filed Nov. 7, 1962, Ser. No. 236,023 6 Claims. (Cl. 200-46) This invention relates to multiple switching units generally, more particularly to an improved controlled multiple switching unit for selectively actuating a plurality of predetermined switching circuits.

Recent advances in electronics instrumentation have given rise to the development of complex multiple switching units having the capability to control multiple circuits in accordance with some predetermined pattern. Pattern controlled multiple switching units normally include a plurality of individual switches which are selectively actuated to achieve a desired controlled switching function. Oftentimes, these multiple switches may be operated through contact with a pre-punched card or similar pattern controller.

The efficiency of an electronic instrument which includes a plurality of individual circuit paths controlled by a multiple switching unit is often seriously limited by the deficiencies inherent in the switching unit utilized. Controlled multiple switching units known to the prior art normally include a plurality of mechanical switches mounted in close proximity with one another. In some electrical units, as in tube testing units, a switch bank may include multiple switches mounted along a common mounting board in closely spaced apertures. Due to this close proximity, it is normally impossible to utilize a wide variety of switches within the multiple switch bank, as the switch type must be limited to mechanical switches having an extremely small diameter, therefore often sacrificing quality for size.

In commonly known switch banks now in use, the individual switching unit normally constitutes a long, slender, sliding switch probe which slides into a bayonet contact when actuated. The switch probes are normally mounted upon a single mounting board, and are selectively actuated when a programmed card having imperforate areas for engaging selective switching probes is moved into contact with the switch bank. Bayonet switches of this type tend to experience contact wear after appreciable periods of usage, and the spreading or deterioration of the switch contacts causes electrical short circuiting within the switch bank. Often, the impact experienced by slender switch probes upon contact with a programmed card and its supporting card carriage causes bending of the switch probes and additional damage to the bayonet contacts. Due to the close proximity between individual switches, a damaged switch contact or switch probe will often make contact with an adjacent probe or contact, thereby causing a short circuit situation or completing an undesired circuit connection. The detection of a single damaged switch within a multiple switching bank is quite difiicult, and therefore, it is often necessary to replace the complete bank upon the malfunctioning of a single switch.

These deficiencies in previously controlled multiple switching units have given rise to the need for an improved multiple switching unit capable of prolonged trouble-free operation. Such a switching unit must incorporate a plurality of individual mechanical switches within a limited space, and each of these switches must be positioned so as to be selectively actuated through contact with a programmed card or controller.

A primary object of this invention is to provide an improved, controlled multiple switching unit including a plurality of individual mechanical switches mounted within a minimum space and adapted for selected actuation by a single program controller.

Another object of this invention is to provide a controlled multiple switching unit including a plurality of mechanical switches mounted within a minimum space which is capable of prolonged trouble free operation.

A further object of this invention is to provide a controlled multiple switching unit including a plurality of laterally spaced, individual mechanical switches mounted upon spaced, superimposed supports, wherein the distance between individual switches is increased by mounting each switch in staggered relationship to corresponding switches on adjacent supports.

Another object of this invention is to provide a controlled multiple switching unit including a plurality of compact, individual mechanical switches which are actuated by reciprocal, non-conductive actuating units mounted for contact with a programmed controller.

A further object of this invention is to provide a controlled multiple switching unit including electronic means for moving a programmed controller into contact with a plurality of reciprocal switch actuating units to cause the selective actuation of individual mechanical switches.

A still further object of this invention is to provide an improved controlled multiple switching unit of simple, inexpensive construction which may he electronically actuated to provide a predetermined selective switching function.

With the foregoing and other objects in view, the invention resides in the following specification and claims, certain embodiments and details of construction of which are illustrated by the specification taken with the accompanying drawings in which:

FIGURE 1 is a perspective view illustrating the controlled multiple switching unit of the present invention.

FIGURE 2 is a partially sectioned view in side elevation of the controlled multiple switching unit of the present invention.

FIGURE 3 is a horizontal sectional view of the invention taken along lines 33 of FIGURE 2.

FIGURE 4 is a sectional view illustrating the carriage support construction 'of the present invention.

FIGURE 5 is a sectional view taken along lines 55 of FIGURE 1.

FIGURE 6 is a plan view illustrating the latching mechanism of the present invention; and

FIGURE 7 is a schematic diagram illustrating the electrical drive circuitry of the present invention.

Referring now to FIGURE 1, the controlled multiple switching unit of the present invention indicated generally at 10 includes a mounting frame 11 having a lower support plate 12 and an upper support plate 13. Upper support plate 13 is secured to and spaced from lower support plate 12 by a plurality of spacing columns 14. Mounted above the upper support plate 13 are a plurality of mounting plates 15 which serve to support a plurality of button switches 16, as shown in FIGURE 2.

FIGURES 1 and 2 show two mounting plates 15 for illustrative purposes only, and it is quite obvious that any desired number of mounting plates may be included within the multiple switching unit 10. The mounting plates 15 are held in spaced relationship above the upper support plate 13 by means of spacer units 17 which surround mounting bolts 18. Mounting bolts 18 are secured to the upper support plate 13 and pass through suitable apertures provided in the mounting plates 15 and in a switch actuator mounting plate 19. The switch actuator mounting plate 19 is held in superimposed relationship with the mounting plates 15 by spacers 20 which surround the mounting bolts 18. The actuator mounting plate 19 supports a plurality of switch to a point within the actuator mounting plate 19.

3 actuators 21, as illustrated in FIGURE 3, for operation in a manner to be hereinafter described.

A card carriage 22 including an upper plate 23 super imposed upon a lower plate 24 is mounted in spaced relationship above the actuator mounting plate 19, and is supported for reciprocal movement toward and away from the actuator mounting plate 19 and the mounting plates 15. Both the upper and lower plates 23 and 24 are provided with a plurality of apertures 25 which correspond in number and position to the actuating rods 21 and the. button switches 16. Upper plate 23 is cut away, as illustrated at 26 in FIGURE 2, to receive a punched program control element 27. Control element 27 may constitute a punched card or similar control sheet which may be inserted between the upper and lower carriage plates 23 and 24. A microswitch 28 is mounted upon the rear portion of the carriage 22 and is adapted to be contacted by the control card 27 upon the full insertion thereof into the cut-away section 26 between the plates 23 and 24, as is well illustrated by FIGURE 5. Microswitch 28 is electrically connected to control the operation of a drive solenoid unit 29 which is mounted upon the lower support plate 12 of the mounting frame 11. The solenoid drive drive unit 29 furnishes the motive power required to move the carriage 22 toward the mounting plates to enable the actuator units 21 to pass through the apertures 25 in the lower carriage plate 24 to contact the control card 27.

Before a description of the mechanism utilized to control the movement of the carriage 22 relative to the mounting plates 15, a consideration 'of FIGURE 5, which illustrates the switch control function achieved through contact of the actuators 21 with the control element 27 will prove beneficial. Referring to FIGURE 5, it may be noted that the carriage 22 containing the control element 27 has been moved into contact with the switch actuators 21, causing the switch actuators to extend into the apertures 25 in the lower carriage plate 24. In instances where the control element 27 includes punched portions which correspond with the apertures 25 in the lower carriage plate 24, certain switch actuators 21 will pass through the control element 27 and into the apertures 25 in the upper carriage plate 23. However, if the control element 27 contains no individual punched section corresponding with an aperture 25 in the lower carriage plate 24, a switch actuator extending into the aperture 25 will contact the control element 27 and will .be depressed thereby as the carriage 22 moves toward the mounting plates 15. Depression of an actuator 21 will cause the subsequent depression of the corresponding button switch 16 which is contacted by the individual depressed actuator. It should be noted that each actuator 21 includes an actuating rod 30, which is preferably formed from non-conductive material, and which extends from a contact point with a button switch 16 It is noteworthy that the switches 16 are positioned upon the mounting plates 15 in staggered relationship so that no vertical alignment exists between the switches on any mounting plate. This staggered switch relationship permits the employment of high quality button switches having larger diameters rather than small diameter bayonet switches of lower quality, as the disadvantages arising from close switch proximity are eliminated by a staggered positioning of the button switches. Addi- 16, enables the sliding actuator rods 30 to pass through As the trical conduction between adjacent mounting plates.

The upper or contact ends 'of the actuator rods 30 are provided with contact tips 31 which are partially tionally, the staggered positioning of the button switches contained within the actuator mounting plate 19. Contact tips 31 are spring loaded by springs 32, and are capable of biased reciprocal movement relative to the actuator rods 30. Contact tips 31 are provided with an elongated contact end portion 33 which extends upwardly into the apertures 25 in the carriage 22 when the carriage is moved into contact relationship with the actuator units 21. Normally, the contact end portions 33 extend in the same plane, and the acuator contact with the button switches 16 at different levels is achieved through varying the length of the actuator rods 30.

The spring biased action of the actuator tips 31 prevents damage to both the button switches 16 and the control element 27. Normally, the travel of the button switch 16 is extremely limited, but as will be noted from FIGURE 5, the spring biased travel of the actuator tip 31 relative to the actuator 30 is quite extensive. There fore, the springs 32 operate to absorb excessive shocks arising through violent contacts between the contact end sections 33 and the control element 27, thereby preventing damage to both the control element and the but-ton switches 16. Closure of the button switches 16 is achieved after the contacted actuator tips 31 have moved downwardly for a predetermined distance, and this switch closure completes an electrical circuit through the switch output 34 of the aifected button switch 16.

It is quite obvious that in the switch actuator construction previously described, the individual actuator rods 30 could be eliminated and replaced by elongating the buttons of the switches 16 so that they would extend through the mounting plates 15 into the actuator mounting plate 19.

The movement of the carriage 22 toward the mounting plates 15 to achieve contact between the control element 27 and the switch actuators 21 is accomplished by means of a movable cam unit 35 which cooperates with a carriage support unit 36, as illustrated in FIGURES 1 and 2. Carriage support unit 36 consists of four vertically extending support rods 37, each having one end thereof secured to the car-riage 22. The lower ends of the support rods 37 are secured to cam follower rollers 38 which ride in cam slots 39 provided in side plates 40 and 41 of the cam unit 35. The side plates 40 and 41 of the cam unit 35 are provided with roller bearings 42 which facilitate lateral movement of the cam unit 35 relative to the mounting frame 11. As may be seen from FIG- URES 1 and 4, this lateral movement of the cam unit 35 causes the cam followers 38 to change position within the cam slots 39, thereby causing movement of the carriage support rods 37 and reciprocal movement of the carriage 22 either toward or away from the ,mounting plates 15. The support rod-s 37 pass through the mountting plates 15 and the actuator mounting plate 19, and are capable of sliding movement relative thereto.

The drive mechanism for the reciprocal carriage 22 may be observed by referring to FIGURE 3, wherein the structural components of the switching unit 10 of FIG URE 1 which are positioned beneath the upper support plate 13 of the mounting frame 11 are illustrated. With reference to FIGURE 3, it will be noted that the laterally rnovable cam unit 35 includes a center section 43 which extends transversely across the mounting frame 11 to join the side walls 40 and 41 of the cam unit. Thus, the cam unit 35 incorporates an overall configuration which is substantially H-shaped. The solenoid drive unit 29 is mounted upon the lower support plate 12, and, for purposes of illustration, includes two solenoids ,44 and 45 operatively connectedto the center wa1l'43 of the cam unit 35. It is, of course, obvious that drive unit 29 could include any desired number of driving solenoids. Drive solenoid unit 29 is electrically connected to the micro-switch 28 upon the carriage 22, and energization of the solenoid drive unit 29 is achieved through the closing of the microswitch 28 by the control element 27. Upon energization, the solenoid drive unit 29 acts through the connection with the center wall 43 to move the cam unit 35 toward the right side of the switching unit as illustrated in FIGURE 3. This movement of the cam unit 35 causes the carriage 22 to move downwardly toward the mounting plates 15. As the cam unit 35 moves to the right side of the switching unit 10 in FIGURE 3, a projection 46 on the lower edge of the wall 43 is caused to move along a cam surface on a latching member 47. Latching member 47, as may best be observed with reference to FIGURE 6, is pivoted at 48 to the lower support plate 12 of the mounting frame 11. As the center wall 43 of the cam unit 35 moves to the right under the influence of the solenoid drive unit 29, the projection 46 on the bottom portion thereof is caused to ride up the cam surface on the latch 47, thereby moving the latch about the pivot 48 against the spring bias of a spring 50. Spring 50' is secured between the latch 47 and the bottom plate 12 of the support frame 11. When the cam unit 35 reaches the extent of its lateral travel and the control element 27 has been brought into contact with the actuator units 21, the projection 46 will pass beyond a shoulder 49 on the latching unit 47, and the shoulder 49 will snap into place behind the projection 46 to prevent the return movement of the camming unit 35. Latching unit 47 is thus held in locked relationship with the projection 46 on the camming unit 35 as illustrated by FIGURE 6.

A second microswitch 51 is mounted upon the lower support plate 12 of the mounting frame 11, and, as illustrated by FIGURE 3, is positioned to contact the center wall 43 of the cam unit 35 when the cam unit is driven to the terminal point of its lateral movement by the solenoid drive unit 29. At this point, when the latch unit 47 snaps into place to prevent the return movement of the cam unit 35, the microswitch 51 is operated by contact with wall 43 to open the electrical power circuit to the solenoid unit 29, thus preventing further operation of the solenoid uni-t.

After a predetermined switching function has been completed, it becomes desirable to return the switching unit 10 to its original non-operative condition so that a new control element 27 may be inserted to initiate a diiferent switching function. To achieve the discontinuance of a completed switching function, a control switch 52 is manually activated to energize a latch solenoid 53. Latch solenoid 53 is mounted upon the lower plate 12 of the mounting frame 11 and is operatively connected, by means of a mechanical linkage 54, to the latch 47. Operation of the latch solenoid 53 causes the latch 47 to be drawn back from the projection 46 against the bias of the spring 50 so that the projection 46 is permitted to clear the shoulder 49. Thus, the cam unit 35 is free to move to the left of the switch unit 10 of FIGURE 3 and thereby move the carriage 22 away from the mounting plates 15. This return movement of the cam unit 35 is facilitated by the upward spring pressure exerted upon the carriage 22 by the biasing springs 32 of the actuation units 21, and also by a return spring 55 extending between the center wall 43 of the cam unit 35 and the lower support plate 12 of the mounting frame 11.

As the cam unit 35 is returned to its original position by the return spring 55, the microswitch 51 is no longer in contact with the center wall 43 of the cam unit, and, under normal conditions, the solenoid unit 29 would be re-energized by the microswitch 28 to drive the cam unit back to its locked position. However, with reference to FIG- URE 7, it will be noted that the manual switch 52 constitutes a two-pole switch which prevents re-actuation of the solenoid drive unit 29 as the cam unit 35 moves back to its original position. As may be seen from FIGURE 7, the microswitch 51 constitutes a normally closed microswitch, while the microswitch 28 is normally in the open position. Switch 52 is also normally in contact with the contact 56 of FIGURE 7. Thus, upon the energization of microswitch 28 by the control element 27, power flows from an input source 57, through the solenoid drive unit 29, the closed microswitches 51 and 28, and the switch contact 56 to the manual switch 52. The cam unit 35 is thereby moved to its locked position on the support frame 11, and the control element 27 is moved into contact with the actuator units 21. At this point, the microswitch 51 contacts the center wall 43 of the cam unit 35, and the microswitch 51 is thereby opened to break the circuit to the drive solenoid unit 29.

To return the cam unit 35 to its initial position, the switch 52 is manually moved to the contact 58 of FIG- URE 7. With the switch 52 in this position, power is feed from the power input 57 through the latch solenoid 53, the contact 58 and the switch 52. However, the movement of the manual switch 52 away from the contact 56 breaks the circuit from the power input 57 to the solenoid drive unit 29, and therefore the subsequent re-closure of the microswitch 51 does not act to reactivate the solenoid drive unit 29.

The operation of the improved controlled multiple switching unit of the present invention will be readily apparent to those skilled in the art after a consideration of the preceding description taken in conjunction with the illustrated features of FIGURES 1 through 7. The present invention provides a novel, controlled, multiple switching unit which incorporates an improved switch actuating mechanism and a novel switch mounting construction to facilitate the spaced mounting of a plurality of high quality button switches. The arrangement and types of components utilized within this invention may be subject to numerous modifications well within the purview of these inventors who intend only to be limited to a liberal interpretation of the specification and appended claims.

We claim:

1. A controlled multiple switching unit adapted for selective actuation by a programmed control element comprising a mounting frame, a plurality of spaced, superimposed mounting plates secured to said mounting frame, a plurality of laterally spaced switching means mounted upon each said mounting plate, said switching means upon each said mounting plate being positioned in staggered relationship relative to the switching means upon the remaining mounting plates to prevent the vertical alignment of said switching means, carriage means for supporting said programmed control element movably mounted in spaced relationship above said mounting plates, can means movably mounted upon said mounting frame below said mounting plates, said cam means adapted for limited lateral movement relative to said mounting frame and including roller bearing cam following means, support means having one end thereof secured to said carriage means, the opposite end of said support means being provided with a cam follower in contact with said movable cam means, whereby said support means is caused to provide limited reciprocal movement of said carriage means toward and away from said mounting plates upon the movement of said cam means, means mounted upon said mounting frame to cause selective movement of said cam means, and switch actuating means connected to each said switching means, said switch actuating means being positioned to contact said programmed control element upon movement of said carriage means toward said mounting plates to selectively actuate certain of said switching means.

2. A controlled multiple switching unit adapted for selective actuation by a programmed control element comprising, a mounting frame, a plurality of spaced, superimposed mounting plates secured to said mounting frame, a plurality of laterally spaced switching means mounted upon each said mounting plate, said switching means upon each said mounting plate being positioned in staggered relationship relative to the switching means upon the remaining mounting plates to prevent the vertical alignment of said switching means, carriage means for supporting said programmed control element movably mounted in spaced relationship above said'mounting plates, cam means movably mounted upon said mounting frame below said mounting plates, said cam means being adapted for limited lateral movement transversely of said mounting frame, support means having one end thereof secured to -said carriage means, the opposite end of said support means being provided with a cam follower in contact with said cam means, whereby said support means provides limited reciprocal movement of said carriage means toward and away from said mounting plates upon movement of said cam means relative to said mounting frame, solenoid means mounted upon said mounting frame, said solenoid means being attached to drive said cam means relative to said mounting frame, switch actuating means connected to each said switching means, said switch actuating means being positioned to contact said programmed control element upon movement of said carriage means toward said mounting plates to selectively actuate certain of said switching means, and latch means provided upon said mounting frame, said latch means operating to automatically contact and secure said cam means against further movement relative to said mounting frame subsequent to the contact between said switch actuating means and said programmed control element.

3. The controlled multiple switching unit of claim 2 wherein first switch means are mounted upon said carriage means, said first switch means being operative upon contact thereo with said first programmed control element to energize said solenoid means, whereby said cam means is driven relative to said mounting frame to initiate the movement of said carriage means toward said mounting plates.

4. The controlled multiple switching unit of claim 2 wherein second switch means are mounted upon said mounting frame to contact said cam means upon the movement of said cam means into contact with said latching means, said second switch means operating upon contact with said cam means to de-energize said solenoid drive means.

5. The controlled multiple switching unit of claim 4 which includes second solenoid means mounted upon said mounting frame and operatively connected to said latch means, said second solenoid means being operative to withdraw said latch means fromcontact with said cam means, and return spring means extending between said mounting frame and said cam means, said return spring means operating to move said cam means out of contact with said second switchmeans upon the release of said latch means,

each said mounting plate, said switching means upon each said mounting plate being positioned in staggered relationship relative to the switching means upon the remaining mounting plates, whereby said switching means are vertically misaligned, carriage means for receiving said punched control card mounted in spaced relationship above said mounting plates, cam means movably mounted upon said support frame for lateral movement relative thereto, support means having one end thereof secured to said carriage means, the opposite end of said support means being provided with a cam follower in contact with said cam means whereby said support means is caused to selectively move said carriage means toward and away from said mounting plates upon the movement of said cam means, switch actuating means being positioned to contact said punched control card upon movement of said carriage means toward said mounting plates to accomplish the selective actuation of certain of said switching means, solenoid drive means mounted upon said mounting frame and operatively connected to cause movement of said cam means, a first switching means mounted upon said carriage means for engagement with said punched control card, said first switching means operating upon contact with said punched control card to energize said solenoid drive means whereby said cam means is driven to cause movement of said carriage means toward said mounting plates, latch means mounted upon said mounting frame, said latch means operative to engage and secure said cam means against further movement relative to said mounting frame subsequent to the engagement of said switch actuating means with said punched control card, second switch means mounted upon said mounting frame for contact with said cam means upon the contact thereof with said latch means, said second switch means operative upon contact with said cam means to de-energize said drive solenoid means, a latch solenoid secured to said mounting frame and operatively connected to said latch means, said latch solenoid operating to remove said latch means from contact with said cam means to permit return movement thereof relative to said mounting frame, and return spring means extending between said mounting frame and said cam means, said return spring means operative upon the release of said latch means to move said cam means away from said second switch means, thereby causing the movement of said carriage means away from said mounting plates.

References Cited by the Examiner UNITED STATES PATENTS 2,682,581 6/54 ,Roggenstein 20046 2,825,773 3/58. Avdeenko 20046 2,967,916 1/ 61 Williams 20046 X BERNARD A. GILHEANY, Primary Examiner. ROBERT K. SCHAEFER, Examiner. 

1. A CONTRLLED MULTIPLE SWITCHING UNIT ADAPTED FOR SELECTIVE ACTUATION BY A FPROGRAMMED CONTROL ELEMENT COMPRISING A MOUNTING FRAME, A PLURALITY OF SPACED, SUPERIMPOSED MOUNTING PLATES SECURED TO SAID MOUNTING FRAME, A PLURALITY OF LATERALLY SPACED SWITCHING MEANS MOUNTED UPON EACH SAID MOUNTING PLATE, SAID SWITCHING MEANS UPON EACH SAID MOUNTING PLATE BEING POSITIONED IN STAGGERED RELATIONSHIP RELATIVE TO THE SWITCHING MEANS UPON THE REMAINING MOUNTING PLATES TO PREVENT THE VERTICAL ALIGNMENT OF SAID SWITCHING MEANS, CARRIAGE MEANS FOR SUPPORTING SAID PROGRAMMED CONTROL ELEMENT MOVABLY MOUNTED IN SAPCED RELATIONSHIP ABOVE SAID MOUNTING PLATES, CAN MEANS MOVABLY MOUNTED UPON SAID MOUNTING FRAME BELOW SAID MOUNTING PLATES, SAID CAM MEANS ADAPTED FOR LIMITED LATERAL MOVEMENT RELATIVE TO SAID MOUNTING FRAME AND INCLUDING ROLLER BEARING CAM FOLLOWING MEANS, SUPPORT MEANS HAVING ONE END THEREOF SECURED TO SAID CARRIAGE MEANS, THE OPPOSITE END OF SAID SUPPORT MEANS BEING PROVIDED WITH A CAM FOLLOWER IN CONTACT WITH SAID MOVABLE CAM MEANS, WHEREBY SAID SUPPORT MEANS IS CAUSED TO PROVIDE LIMITED RECIPROCAL MOVEMENT OF SAID CARRIAGE MEANS TOWARD AND AWAY FROM SAID MOUNTING PLATES UPON THE MOVEMENT OF SAID CAM MEANS, MEANS MOUNTED UPON SAID MOUNTING FRAME TO CAUSE SELECTIVE MOVEMENT OF SAID CAM MEANS, AND SWITCH ACTUATING MEANS CONNECTED TO EACH SAID SWITCHING MEANS, SAID SWITCH ACTUATING MEANS BEING POSITIONED TO CONTACT SAID PROGRAMMED CONTROL ELEMENT UPON MOVEMENT OF SAID CARRIAGE MEANS TOWARD SAID MOUNTING PLATES TO SELECTIVELY ACTUATE CERTAIN OF SAID SWITCHING MEANS. 